Summary

Chilblain should be a readily available diagnosis amongst family physicians. But with recent changes in the climate and more subtle winters in Hong Kong, chilblain has become more elusive and doctors here have less confidence in its immediate diagnosis. This report depicts the diagnostic challenges and perplexities faced by our doctors in dealing with a case of chilblain. More importantly, it highlights the underlying cause of their confusion which is not out of their microscopic ignorance but rather the changes in disease patterns relating to the macroscopic environment.

摘要

凍瘡本是一種家庭醫生很容易診斷的疾病，但因為氣候 的變化，冬天變得不明顯，凍瘡變得難以捕捉令醫生難以做 出即時的診斷。本報告描述家庭醫生在診斷凍瘡時所遇到的 挑戰和困難，突顯出醫生診症時的迷惑主要在于外在的環境 變化，而非醫生們內在的疏忽。

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Introduction

Progressive global warming has not only produced hotter summers and initiated calls for environmental a l er tn es s , i t has al s o u n k n owin gly aff e ct e d th e presentation and interpretation of certain pathologies in the medical scene. Seen in our western counterparts, chilblain is not an uncommon skin disease. It is naturally less common in countries experiencing tropical climates. Extensive case reports and studies on chilblain in Western countries are available. The situation is very much different in our region. One case report was made in Thai land b y a dermatolog ist wh ere an individual experienced chilblain after exposure to an Australian winter. For this case, extensive investigations were performed due to diagnostic challenges.¹ With Hong Kong experiencing hotter winters, the incidence of chilblain has decreased such that doctors now do not have much confidence to diagnose this condition immediately. Indeed unnecessary investigations may be performed for the diagnosis. This case report also aims to remind doctors on the subtle and intriguing relationship between the natural elements and our health.

Clinical information

A 15 years old young gentleman, Andy, was seen in a General Outpatient Clinic (GOPC) on one evening in mid-February 2008. He presented with a two day history of a painful nodule over the lateral side of his right middle finger just distal to the proximal interphalangeal joint (PIPJ). There had been no history of apparent trauma. The nodule had slightly grown larger and becoming progressively tender. There was no similar lesion elsewhere and Andy was systemically well and afebrile. It was a bluish reddish nodule which was 1 cm in diameter and very tender. A faint mark could be seen in the centre of the nodule which slightly resembled a bite mark by insects. The foremost diagnosis by the attending physician at that time was cellulitis from an insect bite, which is common in Hong Kong. The patient was prescribed a course of ampicillin and cloxacillin and also neomycin cream. As Andy was well and afebrile, and the nodule was a very localized problem, the attending physician was not overly concerned with the patient’s condition in a busy night clinic setting.

During the same clinic session, 14 years old Be nj amin c ame with h is mo the r pre se nting wi th spontaneous onset of very similar nodules over his fingers and toes. They were mildly itchy and slightly painful. Simi lar ly, the re was n o pr ior h istory o f tra uma. Benjamin’s condition was preceded by mild coryzal symptoms, including headache and dizziness without any fever. Other large joints were not affected and there were no similar lesions elsewhere over the body. He had no previous similar episodes and had no previous medication intake. Benjamin had no prior skin problems and enjoyed good past health. He had no pets at home and had not been on any recent travel. There was no family history of autoimmune problems. There had been no contacts made specific to his toes and fingers.

On physical examination, there were blanchable reddish nodules ranging from 0.5 to 1 cm diameter over his right ring finger and the left index finger, just lateral to the small joints. He also had similar lesions near the interphalangeal joints of his toes. The nodules had well demarcated borders with smooth surface. There was no scaling. Similar to Andy’s, there was a central mark inside the nodules; but Benjamin’s lesions were less tender. There was no associated joint swelling or effusion. The rest of the body skin was normal.

Seeing two similar cases in the adolescent age group in the same community setting raised suspicions of a spreading viral exanthema, since the clinical symptoms of redness, pain and swelling indicated an inflammatory or infectious process. Blood count with differentials, liver and renal function tests for Benjamin were done to look for signs of an underlying infection. Andy’s case was also put in file for further review and planned for calling back for further investigation if necessary. The two cases were discussed amongst our doctors within the cluster who had also seen cases with similar presentation from various age groups and both sexes.

A few days later, a Mrs. Chan who was a middle aged cleaner in a public hospital was seen at the hospital’s staff clinic with a very similar presentation. She was very much afraid that she was having a serious attack of gout as her husband had frequent gouty attacks and finally died of renal failure. Her presentations were atypical of gout and investigations performed before were normal. The main difference between Mrs Chan and the two teenagers was that she had had previous similar episodes once every 1-2 years for six years. On reviewing her past records, it was noted that these lesions occurred only in the cold seasons. She had been referred to various specialists including rheumatologists as she was suspected to have some kind of autoimmune disease with painful swellings over the knuckle areas. Immunology markers were absent and she was subsequently discharged from the rh euma tolo g y c l in ic . Sh e was a l so r e fe r r e d to dermatologists; but her nodules had subsided by the time she was seen and so was duly discharged without her ailment being explained.

After extensive literature searching, Mrs Chan’s condition was found to be compatible with chilblains. Senior colleagues who had followed up the two teenage boys readily made the diagnosis of chilblain from their experience. General advice for protecting against the natural elements and cold weather was given. Mrs Chan was also given some NSAIDS to relieve the pain. All the patients were also reassured this was a self limiting condition. With the gradual warming of the weather, all these cases resolved spontaneously without any scarring or residual problems.

Pathophysiology

Chilblains (Pernio), also called “cold sores” and “little turnips” in our local population, are painful inf lammat io n o f th e sk in , u su al ly in vo lv in g th e extremities, due to exposure to cold. It is generally believed that it involves an abnormal vascular response to cold temperature, dermal inflammation and a superficial oedema. It is more frequent when damp or humid conditions coincide. Minor trauma also may predispose the acral parts to symptomatic lesions in otherwise appropriate weather conditions.²

It is more common in areas having long cold winters. Our local doctors are less experienced meeting this condition due to the relatively “warm” and short winters here. The true incidence is not known as many cases frequently went unrecognized or misdiagnosed.² An epidemiology study in Pakistan showed that in moderately c old wea the r a re as , o utd oo r work er s and yo un g adolescents were more likely to develop chilblains. The disease usually lasted longer in females.³ Another case report in Colorado in USA described five adolescent girls having chilblains, all of whom were thin. The proposed mechanism was that thin body habitus may be associated with increased cutaneous vasoactivity.⁴ The situation is now thought to be it becomes more troublesome if it involves occupational exposure to the cold, like the milkers in New Zealand.⁵ It is said some milkers may even quit their job because of annual recurrence.

Chilblains usually present as single or multiple e r y t h ema to u s , p u r p l i s h an d e d ema t o u s l e s io n s accompanied by intense pain, itching or a burning sensation (Figure 1). It is usually diagnosed clinically after a history of cold exposure with typical physical findings affecting the extremities.

It is generally believed that chilblains are associated with malnutrition and autoimmune disease. Patients with anorexia nervosa (AN) had been reported to have chilblains. Suggested mechanisms include an altered thermoregulation and a hyperactive peripheral vascular response to cold.^6,7 Another adolescent girl with coeliac disease was also reported to present with chilblains.⁸ Cutaneous manifestation with chilblains for lupus erythematosis (lupus pernio) and sarcoidosis have been well documented.^9,10 It is sometimes diff icult to differentiate between idiopathic chilblains or lupus pernio. In such cases, checking immune markers, skin biopsy or referral to a dermatologist would be necessary. The most characteristic histological findings of chilblains include superficial and deep T-cell perivascular infiltrates associated with dermal oedema and necrotic keratinocytes. These findings can help differentiate idiopathic chilblains from lupus. Immunohistochemistry is of no use in this differentiation.¹¹

Cases of chronic myeloid leukemia and breast cancer presenting with metastatic skin lesions that were initially wrongly diagnosed as chilblains were also reported.^{12, 13} However the fact that chilblains usually have bilateral involvement provides some hints on diagnosis. We should always keep an open mind on our diagnosis, especially in cases with prolonged recovery.

Chilblains is only one type of cold inflicted skin injuries. Diseases in the same spectrum include cold panniculitis, Raynaud’s phenomenon and frostbite. Cold panniculitis involves the deeper subcutaneous fat layer. Raynaud’s phenomenon involves mainly blood vessels and has a characteristic colour change pattern. The duration is usually much shorter, resolving within hours or days. Frostbite is another disease commonly seen in cold areas, with freezing of tissue and resultant tissue necrosis.

The main causative factor for chilblain is cold exposure. Thus prevention is of greatest importance. Measures include avoiding exposure to cold water or wind, wearing enough clothings, gloves and socks to conserve heat, and to take enough food and fluid to maintain metabolic heat production. Quitting smoking can also help.

Non-steroidal anti-inflammatory drugs can be used for pain control. Topical steroids and, in severe cases, a short course of oral steroid may also be beneficial.¹⁴ Other possible therapies include the use of nifedipine.¹⁵ A recent study in India found that nifedipine 10mg tds (with subsequent 20mg bd maintenance dose) was superior to diltiazem.¹⁶

Discussion

Diagnostic Challenge

Th is may seem to be a s impl e c ase of easi ly d ia gn os ab le c hi lb la in s. Howe ve r, Mrs Chan has actually be en su ffer ing f rom inte nse f ear desp ite having profuse referrals and investigations, instead of being reassured that her condition is a self limiting one brought on by cold damage. Chilblain may be a common diagnosis in colder regions, but Hong Kong enjoys a tropical climate with only mild winters. The reason that this year brought a profuse number of presentations with chilblain was that Hong Kong had just experienced an exceptionally cold winter. The Hong Kong Observatory recorded the longest cold spell in Hong Kong since 1986, with the minimum temperature falling to below 12oC for 21 consecutive d a y s . Du r i n g t h i s p e r i o d , t h e me an mi n imum temperature recorded at the Hong Kong Observatory was 9.9 degrees, the second lowest for the same period (January 24 – February 13) of the year since records began in 1885.¹⁷

It is thus logical to think that the less tropically adapted the residents are to the cold weather, the greater the impact on our bodies would be with a sudden temperature change. Residents in Hong Kong also may not have appropriate clothings for a sudden change in weather such as gloves and mittens compared with their Northern Hemisphere counterparts. Senior colleagues have also noticed more frequent episodes of chilblains in domestic helpers from the Philippines or Indonesia during their first winters in Hong Kong. This observation is likely due to their maladaption but there have been no journal reports on this subject. In our locality, the elderly pop ulation ha ve de finite ly mo re ex perie nce with chilblains and did not seek medical attention – rather it was children and the young population who came to seek advice as they were worried about the sudden eruptions of painful nodules.

Early recognition and diagnosis of this condition help in preventing unnecessary investigations and treatment which may carry possible adverse effect such as a biopsy.¹⁸

The impact of climatic changes and global warming on disease patterns

Our senior colleagues also seemed to be more confident in the diagnosis of chilblains probably due to colder winters in Hong Kong in the past. Future generations of primary care physicians in Hong Kong may encounter less chilblains as there have been vast reports by the Hong Kong Observatory with supercomputer simulations that Hong Kong could very well lose its winter secondary to green house gas emissions and further urbanization¹⁹ (Tables 1 & 2).

Key messages

1. Climatic and environmental changes affect and can relate to various skin conditions.
2. Di s e a s e p a t t e r n s a r e p r o n e to d i f f e r e n t presentations with environmental changes.
3. Chilbla in should be part of the diffe rentia l diagnos is unde r spec ific c ircumstance s – an unsuspecting population faced with a sudden weather change.

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Reference